Kelvin degrees determine the color of the light, not its intensity. 2700K gives a warm, distinctly yellowish color, while 3000K is warm but less yellow and more balanced.
4000K tends towards natural white and shows details more clearly, while 6000K provides cool white light and is slightly bluish.
The correct choice depends on the ambiance of the space and its intended use, keeping in mind that a higher Kelvin number does not mean increased light intensity.